Predictive factors of thromboembolic complications in patients with esophagogatric adenocarcinoma undergoing preoperative chemotherapy

The impact of platelets on the metastatic potential of tumour cells

In cancer, activation of platelets by tumor cells is critical to disease progression. Development of precise antiplatelet targeting may improve outcomes from anticancer therapy. Alongside a distinct shift in functionality such as pro-metastatic and pro-coagulant properties, platelet production is often accelerated significantly early in carcinogenesis and the cancer-associated thrombocytosis increases the risk of metastasis formation and thromboembolic events. Tumor-activated platelets facilitate the proliferation of migrating tumor cells and shield them from immune surveillance and physical stress during circulation. Additionally, platelet-tumor cell interactions promote tumor cell intravasation, intravascular arrest, and extravasation through a repertoire of adhesion molecules, growth factors and angiogenic factors. Particularly, the presence of circulating tumor cell (CTC) clusters in association with platelets is a negative prognostic indicator. The contribution of platelets to the metastatic process is an area of intense investigation and this review provides an overview of the advances in understanding platelet-tumor cell interactions and their contribution to disease progression. Also, we review the potential of targeting platelets to interfere with the metastatic process.

Targeting Platelet Activation Pathways to Limit Tumour Progression: Current State of Affairs

The association between cancer and a hypercoagulatory environment is well described. Thrombotic complications serve not only as a major mortality risk but the underlying molecular structure and function play significant roles in enhancing tumour progression, which is defined as the tumour's capacity to survive, invade and metastasise, amongst other hallmarks of the disease. The use of anticoagulant or antiplatelet drugs in cardiovascular disease lessens thrombotic effects, but the consequences on tumour progression require interrogation. Therefore, this review considered developments in the management of platelet activation pathways (thromboxane, ADP and thrombin), focusing on the use of Aspirin, Clopidogrel and Atopaxar, and their potential impacts on tumour progression. Published data suggested a cautionary tale in ensuring we adequately investigate not only drug-drug interactions but also those unforeseen reciprocal interactions between drugs and their targets within the tumour microenvironment that may act as selective pressures, enhancing tumour survival and progression.

Incidence and Determinants of Chemotherapy Associated Thromboembolic Events among Ethiopian Patients Treated for Solid Malignancy: A Retrospective Cross-Sectional Study

Venous thromboembolism is a common problem in patients treated for cancer, although the reported incidence varies widely between studies. This was the first study in its kind in Ethiopia and aimed to assess the incidence and determinants of chemotherapy associated thromboembolic events among patients treated for solid malignancy. An institution-based retrospective cross-sectional study was conducted from 1st March to 1st June, 2019 at adult oncology center of Tikur Anbessa Specialized Hospital. Systematic random sampling technique was employed to recruit 423 study participants. Patients who have received at least a single cycle of any chemotherapy regimen were included in the study. Khorana risk assessment tool was used to predict chemotherapy associated thrombosis. Descriptive statistics were used to summarize the data while multivariable logistic regression was employed to explore associations among variables of interest. The median age of study participants was 43 years, which ranged from 14 to 83 years. Majority of the study participants were treated for breast cancer. Thromboembolic events encountered in 43(10.2%) of patients, from which the commonest one being deep venous thrombosis 36 (85.7%), followed by myocardial infarction 5(11.9%). In multivariable logistic regression, blood transfusion, a primary site of cancer with gastrointestinal malignancy and performance status showed statistically significant association towards the occurrences of thromboembolic events. The incidence of chemotherapy associated thromboembolic events among patients treated for solid malignancy was comparable to other studies. Hence, other prospective randomized trials are needed to see the importance of thrombo-prophylaxis in such high-risk patients.

Thromboembolic Events Burden in Patients With Solid Tumors and Their Predisposing Factors

Introduction: The relationship between cancers and thromboembolic events is well established. In our study, we aim to determine the burden of thromboembolic events in patients with solid tumors and identify the risk factors related to their development.

Materials & Methods: Data on patients with solid tumors and thromboembolism between January 2013 and September 2014 were collected and analyzed.

Results: During the study period 174 patients were identified. Of which, 172 (98.9%) had venous thrombus embolism, 137 (79%) were diagnosed with deep vein thromboses, 67 (38.5%) with pulmonary embolism, 84 (48.3%) were symptomatic and 90 (51.7) were incidental at diagnosis. The most common patients and disease characteristics were female sex, high body mass index (BMI), metastatic stage, colorectal and breast primaries, and anti-neoplastic therapy.

Conclusion: Our study confirmed the high burden of thromboembolic events in cancer patients and the relevant factors associated with its development.

Venous Thromboembolism Following Major Abdominal Surgery for Cancer: A Guide for the Surgical Intern

BACKGROUND

Venous thromboembolism (VTE) is a term used to compositely describe deep vein thrombosis (DVT) and pulmonary embolism (PE). Overall, the incidence of VTE after major abdominal and pelvic surgery has been reported to be between 10% and 40%.

OBJECTIVE

To estimate the incidence of post-operative VTE in patients undergoing major abdominal surgery for cancer, to identify risk factors associated with VTE, and to assess available thromboprophylaxis tools.

METHODS

A Medline and Cochrane literature search from database inception until February 1st, 2021 was performed according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines.

RESULTS

Thirty-one studies met our eligibility criteria and were included in the current review. In total, 435,492 patients were identified and the overall incidence of VTE was 2.19%( 95% CI: 1.82-2.38). Τhe following risk factors were associated with VTE: smoking, advanced age (>70 years), a history of diabetes mellitus, American Society of Anesthesiologists' (ASA) classification of Physical Health class III or IV, a history of cardiovascular or pulmonary disease, a history of DVT or PE, elevated plasma fibrinogen level, c-reactive protein (CRP) level, cancer stage III or IV, postoperative acute respiratory distress syndrome (ARDS), prolonged postoperative hospital stay, previous steroid use, history of Inflammatory Bowel Disease (IBD), heart failure and neoadjuvant and adjuvant chemotherapy.

CONCLUSION

VTE remains an important complication after major abdominal surgery for cancer and seems to increase mortality rates.

Prophylaxis Against Thromboembolic Events During Chemotherapy for Germ Cell Cancer

INTRODUCTION

Patients with advanced germ cell tumors (GCT) receiving cisplatin-based chemotherapy have high rates of thromboembolic events (TEE) which can negatively affect their overall survival. While primary TEE prophylaxis during chemotherapy may prevent these events, it is unclear which patients will benefit in this setting.

MATERIALS AND METHODS

A review of PubMed/Medline was conducted in December 2020 and all pertinent articles were evaluated for relevancy and quality of data for inclusion in the review.

RESULTS

Studies on patients receiving initial cisplatin-based chemotherapy for advanced GCT have reported up to a 19% rate of TEE. This high rate may be associated with multiple factors including retroperitoneal lymphadenopathy, advanced clinical stage, high risk Khorana scores and presence of a central line. Large phase III clinical trials have demonstrated the benefit of low-molecular-weight-heparin and direct oral anticoagulants for primary prophylaxis and against recurrent TEE. However, primary prophylaxis is currently underutilized with GCT patients starting chemotherapy.

CONCLUSION

Precise models to predict TEE risk and consideration of anticoagulation are difficult to develop owing to the relatively uncommon nature of GCT and lack of representation in primary TEE prophylaxis clinical trials. Despite these limitations, we believe that the benefits of prophylactic anticoagulation outweigh the risk of major bleeding in select GCT patients with higher risk of TEE. We have developed a simple algorithm to help guide TEE prophylaxis selection based on patient factors and route of chemotherapy administration. Given the high rate of TEE in GCT patients, we believe better utilization of primary prophylaxis in patient starting cisplatin-based chemotherapy will have clinical benefit.

Risk Factors of Fluoropyrimidine Induced Cardiotoxicity among Cancer Patients: A Systematic Review and Meta-analysis

Cancer patients experienced an increased risk of cardiotoxicity during fluoropyrimidine-based chemotherapy (5-fluorouracil or capecitabine). We searched PubMed, PsycINFO, IPA, CINAHL, Web of Science, and ClinicalTrials.gov for studies published between January 1, 1990 and December 31, 2019, in English, examining risk factors for cardiotoxicity induced by fluoropyrimidine. Included study-level data were converted to risk ratios (RRs) and pooled RRs were calculated for meta-analyses using a random-effects method. Among 690 publications identified for abstract and title screening, 22 unique studies were included in the review, and 20 had sufficient data for meta-analyses. Results indicated that patients undergoing capecitabine-based combination therapy had a higher risk than those with monotherapy (pooled RR = 1.61). Patients with pre-existing cardiac disease (pooled RR = 3.26), hypertension (pooled RR = 1.52) or smoking (pooled RR = 2.22) also had higher risks than their counterparts. Developing risk assessment tools to mitigate the risk could be a viable strategy to improve outcomes for cancer patients undergoing fluoropyrimidine-based treatments.

Thromboembolic and bleeding complications in patients with oesophageal cancer

BACKGROUND

In patients who undergo curative treatment for oesophageal cancer, risk estimates of venous thromboembolism (VTE), arterial thromboembolism and bleeding are needed to guide decisions about thromboprophylaxis.

METHODS

This was a single-centre, retrospective cohort study of patients with stage I-III oesophageal cancer who received neoadjuvant chemoradiation followed by oesophagectomy. The outcomes VTE, arterial thromboembolism, major bleeding, clinically relevant non-major bleeding and mortality were analysed for four consecutive cancer treatment stages (from diagnosis to neoadjuvant chemoradiotherapy, during neoadjuvant treatment, 30-day postoperative period, and up to 6 months after postoperative period).

RESULTS

Some 511 patients were included. The 2-year survival rate was 67·3 (95 per cent c.i. 63·2 to 71·7) per cent. During the 2-year follow-up, 50 patients (9·8 per cent) developed VTE, 20 (3·9 per cent) arterial thromboembolism, 21 (4·1 per cent) major bleeding and 30 (5·9 per cent) clinically relevant non-major bleeding. The risk of these events was substantial at all treatment stages. Despite 30-day postoperative thromboprophylaxis, 17 patients (3·3 per cent) developed VTE after surgery. Patients with VTE had worse survival (time-varying hazard ratio 1·81, 95 per cent c.i. 1·25 to 2·64). Most bleeding events occurred around the time of medical intervention, and approximately one-half during concomitant use of prophylactic or therapeutic anticoagulation.

CONCLUSION

Patients with oesophageal cancer undergoing neoadjuvant chemoradiotherapy and surgery are at substantial risk of thromboembolic and bleeding events throughout all stages of treatment. Survival is worse in patients with thromboembolic events during follow-up.

The aegis: platelets as biomarkers of tumor progression

There is increasing awareness that platelets play a significant role in creating a hypercoagulable environment that mediates tumor progression, beyond their classical hemostatic function. Platelets have heterogenic responses to agonists, and differential release and uptake of bioactive molecules may be manipulated via reciprocal cross-talk with cells of the tumor microenvironment. Platelets thus promote tumor progression by enhancing tumor growth, promoting the development of tumor-associated vasculature and encouraging invasion. In the metastatic process, platelets form the shield that protects tumor cells from high-velocity forces and immunosurveillance, while ensuring the establishment of the pre-metastatic niche. This review presents the complexity of these concepts, considering platelets as biomarkers for diagnosis, prognosis and potentially as therapeutic targets in cancer.

The Khorana score for prediction of venous thromboembolism in cancer patients: a systematic review and meta-analysis

We aimed to evaluate the performance of the Khorana score in predicting venous thromboembolic events in ambulatory cancer patients. Embase and MEDLINE were searched from January 2008 to June 2018 for studies which evaluated the Khorana score. Two authors independently screened studies for eligibility, extracted data, and assessed risk of bias. Additional data on the 6-month incidence of venous thromboembolism were sought by contacting corresponding authors. The incidence in each Khorana score risk group was estimated with random effects meta-analysis. A total of 45 articles and eight abstracts were included, comprising 55 cohorts enrolling 34,555 ambulatory cancer patients. For 27,849 patients (81%), 6-month follow-up data were obtained. Overall, 19% of patients had a Khorana score of 0 points, 64% a score of 1 or 2 points, and 17% a score of 3 or more points. The incidence of venous thromboembolism in the first six months was 5.0% (95%CI: 3.9-6.5) in patients with a low-risk Khorana score (0 points), 6.6% (95%CI: 5.6-7.7) in those with an intermediate-risk Khorana score (1 or 2 points), and 11.0% (95%CI: 8.8-13.8) in those with a high-risk Khorana score (3 points or higher). Of the patients with venous thromboembolism in the first six months, 23.4% (95%CI: 18.4-29.4) had been classified as high risk according to the Khorana score. In conclusion, the Khorana score can be used to select ambulatory cancer patients at high risk of venous thromboembolism for thromboprophylaxis; however, most events occur outside this high-risk group.